I am about to drop a 305 TPI in my 89. I'm told that the manual 305 makes more power (220hp) than the auto 305 (195 hp). WHY??

The camshaft in the manual cars are much bigger. But, the 85 models with an automatic trans have the hotter cam too.There may also be some cylinder head variations among the 305 TPI's as well. But the cam is the biggest difference among the engines.

look up the tech articles. the first (85) tpi 305 had something like 210-215 hp and they dropped down in 86. they gradually boosted them back up to 220 then by 92. during that duration there were a couple of cams they used in different vehicle. best thing to do is to just get a hotter cam anyway.

go ahead and do a DCR calculation. that should tell you what cam you should run. bigger isn't always better, especially with smaller cubic inch engines. big cams bleed off cylinder pressure, which is where you develop your power from. take a look at the quench too. good luck.

From my experience, go bigger the first time, don't have to do it over and over.

All that power is lost through the torque converter